1. Technical Field
This application relates to an improved glass cleaning composition that contains either ethylene glycol monohexyl ether (EGHE), or N-Octyl Pyrrolidone (NOP), or a combination of both. The composition further comprises a surfactant. The improved formulation makes use of an unexpected synergetic effect of the aforementioned components to improve cleaning and reduce streaking when the composition is used to clean glass surfaces.
2. Description of the Related Art
Keeping glass clean and shiny significantly enhances the appearance of a home or a car. A popular method of cleaning glass is by applying a glass cleaning composition on the surface of the glass and wiping it off using soft, clean and lint-free clothes or towels. Conventional cleaning compositions are formulated to remove dirt and soils from the glass surface, wherein the dirt and soils may comprise either organic or inorganic substances, or a mixture of both.
Many glass cleaning products are sold commercially, which typically contain a surfactant, an organic solvent or solvent system, a pH-adjusting agent such as ammonia or acetic acid, a detergent builder, a hydrotrope, a fragrance, a dye, and water. WINDEX® and GLASS PLUS® are representative commercially available products.
The effectiveness of the cleaning composition can be reduced by a phenomenon called streaking, wherein a noticeable streak of dirt remains attached to the glass surface after cleaning. While the streak maybe residual dirt not completely removed by the cleaning composition, it is often caused by the improperly formulated cleaning composition itself, such as deposition of solid components of the composition or hazing caused by residual solvent.
Improving cleaning performance without leaving visible streaks has always been an important goal in formulating glass cleaners. Finding a suitable solvent or solvent system has been a key challenge to achieving better cleaning without streaking. For example, the commercially available glass cleaning products sold under the GLASS PLUS® trademarks have a organic solvent system comprising a mixture of ethylene glycol monobutyl ether (EGBE) and isopropyl alcohol. U.S. Pat. No. 5,750,482 to Cummings discloses the formulation of ethylene glycol monohexyl ether (EGHE) into a glass cleaning composition to significantly improve the cleaning performance of a glass cleaner without streaking. Cummings also discloses the use of EGBE as a high boiling point organic co-solvent to further enhance the cleaning performance of the composition.
EGBE is recently being reviewed by the Environmental Protection Agency (EPA) for potential health risks. Providing a component to replace EGBE in the formulation while maintaining or improving the glass cleaning performance of a composition without causing streaking is a key need.
Thus, there is a need for an improved glass cleaning composition that can both improve cleaning and remain substantially streak-free.